Exploiting Contextual Information for Prosodic Event Detection Using Auto-Context

Prosody and prosodic boundaries carry significant information regarding linguistics and paralinguistics and are important aspects of speech. In the field of prosodic event detection, many local acoustic features have been investigated; however, contextual information has not yet been thoroughly exploited. The most difficult aspect of this lies in learning the long-distance contextual dependencies effectively and efficiently. To address this problem, we introduce the use of an algorithm called auto-context. In this algorithm, a classifier is first trained based on a set of local acoustic features, after which the generated probabilities are used along with the local features as contextual information to train new classifiers. By iteratively using updated probabilities as the contextual information, the algorithm can accurately model contextual dependencies and improve classification ability. The advantages of this method include its flexible structure and the ability of capturing contextual relationships. When using the auto-context algorithm based on support vector machine, we can improve the detection accuracy by about 3% and F-score by more than 7% on both two-way and four-way pitch accent detections in combination with the acoustic context. For boundary detection, the accuracy improvement is about 1% and the F-score improvement reaches 12%. The new algorithm outperforms conditional random fields, especially on boundary detection in terms of F-score. It also outperforms an n-gram language model on the task of pitch accent detection

Intonational categories and continua in American English rising nuclear tunes

The present study tests a prediction from the prevalent Autosegmental-Metrical (AM) model of American English intonation: the existence of distinct phonological contrasts among nuclear tunes composed of a pitch accent (here H*, L+H*, L*+H), phrase accent (H-, L-) and boundary tone (H%, L%), which in combination yield an inventory of 12 tonally distinct nuclear tunes. Using an imitative speech production paradigm and AX discrimination task with L1 speakers of Mainstream American English (MAE)we test the extent to which each of 12 predicted tunes is distinct from the others in the production and perception of intonation . We tackle this question with a series of analytical methods. We use GAMM modeling of time-series F0 trajectories to test for differences among all of the twelve nuclear tunes, and compare these results to a method that does not rely on pre-defined tune categories, k-means clustering for time-series data, to discover emergent classes of tunes in a “bottom-up” fashion. We complement these timeseries analyses with an analysis of the temporal tonal center of gravity (TCoG) over the F0 trajectories of nuclear tunes to assess tonal timing distinctions and their relation to top-down tune classes (defined by the AM model) and bottom-up classes (emergent from clustering). Production results are further compared to perceptual discrimination responses, which together point to a hierarchy of distinctions among nuclear tunes: a set of primary tunedistinctions are emergent in clustering and always distinct in perception. Other tune distinctions, although evident in top-down analyses of (labeled) F0 trajectories, are lost in emergent clusters, limited in magnitude and scope, and often confused in perception. Results are discussed in terms of implications for a theory of intonational phonology

A Phonetic model of English intonation

This thesis proposes a phonetic model of English intonation which is a system for linking the phonological and F₀, descriptions of an utterance.It is argued that such a model should take the form of a rigorously defined formal system which does not require any human intuition or expertise to operate. It is also argued that this model should be capable of both analysis (F₀ to phonology) and synthesis (phonology to F₀). Existing phonetic models are reviewed and it is shown that none meet the specification for the type of formal model required.A new phonetic model is presented that has three levels of description: the F₀ level, the intermediate level and the phonological level. The intermediate level uses the three basic elements of rise,fall and connection to model F₀ contours. A mathematical equation is specified for each of these elements so that a continuous lb contour can be created from a sequence of elements. The phonological system uses H and L to describe high and low pitch accents, C to describe connection elements and B to describe the rises that occur at phrase boundaries. A fully specified grammar is described which links the intermediate and F₀ levels. A grammar is specified for linking the phonological and intermediate levels, but this is only partly complete due to problems with the phonological level of description.A computer implementation of the model is described. Most of the implementation work concentrated on the relationship between the intermediate level and the F₀ level. Results are given showing that the computer analysis system labels F₀ contours quite accurately, but is significantly worse than a human labeller. It is shown that the synthesis system produces artificial F₀ contours that are very similar to naturally occurring F₀ contoursThe thesis concludes with some indications of further work and ideas on how the computer implementation of the model could be of practical benefit in speech synthesis and recognition

Prosodic detail in Neapolitan Italian

Recent findings on phonetic detail have been taken as supporting exemplar-based approaches to prosody. Through four experiments on both production and perception of both melodic and temporal detail in Neapolitan Italian, we show that prosodic detail is not incompatible with abstractionist approaches either. Specifically, we suggest that the exploration of prosodic detail leads to a refined understanding of the relationships between the richly specified and continuous varying phonetic information on one side, and coarse phonologically structured contrasts on the other, thus offering insights on how pragmatic information is conveyed by prosody

Prosodic detail in Neapolitan Italian

Recent findings on phonetic detail have been taken as supporting exemplar-based approaches to prosody. Through four experiments on both production and perception of both melodic and temporal detail in Neapolitan Italian, we show that prosodic detail is not incompatible with abstractionist approaches either. Specifically, we suggest that the exploration of prosodic detail leads to a refined understanding of the relationships between the richly specified and continuous varying phonetic information on one side, and coarse phonologically structured contrasts on the other, thus offering insights on how pragmatic information is conveyed by prosody

Prosodic detail in Neapolitan Italian

Recent findings on phonetic detail have been taken as supporting exemplar-based approaches to prosody. Through four experiments on both production and perception of both melodic and temporal detail in Neapolitan Italian, we show that prosodic detail is not incompatible with abstractionist approaches either. Specifically, we suggest that the exploration of prosodic detail leads to a refined understanding of the relationships between the richly specified and continuous varying phonetic information on one side, and coarse phonologically structured contrasts on the other, thus offering insights on how pragmatic information is conveyed by prosody

Prosodic description: An introduction for fieldworkers

This article provides an introductory tutorial on prosodic features such as tone and accent for researchers working on little-known languages. It specifically addresses the needs of non-specialists and thus does not presuppose knowledge of the phonetics and phonology of prosodic features. Instead, it intends to introduce the uninitiated reader to a field often shied away from because of its (in part real, but in part also just imagined) complexities. It consists of a concise overview of the basic phonetic phenomena (section 2) and the major categories and problems of their functional and phonological analysis (sections 3 and 4). Section 5 gives practical advice for documenting and analyzing prosodic features in the field.National Foreign Language Resource Cente